Apparatus for electroplating articles



NOV. 1 E' SOLECKl APPARATUS FOR ELECTROPLATING ARTICLES Filed June 13, 1951 5 Sheets-Sheet l ATTORNEY Nov. 22, 1955 J. E. soLEcKl 2,724,590

APPARATUS FOR ELECTROPLATING ARTICLES Filed June 13, 1951 5 Sheets-Sheet 2 INVENTOR: J. E. SOL ECKI ATTORNEY Nov. 22, 1955 Filed June 13, 1951 FIGB APPARATUS J. E. SOLECKI FOR ELECTROPLATING ARTICLES 5 Sheets-Sheet 5 INVENTOR.- J. E. SOLECKI ATTORNEY Nov. 22, 1955 .1. E. soLEcKl APPARATUS FOR ELECTROPLATING ARTICLES 5 Sheets-Sheet 4 Filed June 13, 1951 INVENTOR.- J. E. S O L E C K l FIGA ATTORNEY J .E. soLEcKl 2,724,690

Novv 2 2, 1955 Filed June 15 1951 U INVENTOR.

J. E. SOLECKI BY MM ATTORNEY United States Patent O Y 2,724,690 APPARATUS FOR ELECTROPLATING ARTICLES John E. Solecki, Indianapolis, Ind., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application June 13, 1951, Serial No. 231,344

9 Claims. (Cl. Zim-204) This invention relates to apparatus for electroplating articles, and more particularly to apparatus for goldplating articles.

In 'the electroplating of articles with precious metal, such as gold, platinum and the like, it is highly desirable tol closely regulate the amount of the precious metal applied to each article to be plated. While such control is possible on a small scale production, there has been no automatic apparatus for large scale commercial controls for electroplating precious metals.

An object of the invention is to provide new and improved apparatus for electroplating articles.

A further object of the invention is to provide new and improved apparatus for gold plating articles.

Another object of the invention is to provide new and improved apparatus for closely controlling the electroplating of precious metals on articles.

An apparatus illustrating certain features of the invention may include an electroplating bath, means for advancing articles through the bath, means for forcing a predetermined quantity of electricity through each of the articles in the bath to plate a predetermined amount of metal on the articles, and means for removing the articles from the bath.

A complete understanding of the invention may be obtained from the following detailed description of an apparatus forming a specific embodiment thereof, when read in conjunction with the appended drawings, in which Fig.'l is a top plan view of an apparatus forming a specific embodiment of the invention;

Fig. 2 is a vertical section of the apparatus taken along line 2--2 of Fig. 1;

Fig. 3 is a schematic view of the control circuit forming part of the apparatus shown in Fig. 1;

Fig. 4' is ,another portion of' the 'control circuit;

IFig.y 5 is a schematic view of a portion of the control circuit shown in Fig. 3;

Fig. 6 is a fragmentary, front elevation of the apparatus shown in Fig. l;

Fig. 7 is an enlarged, fragmentary, vertical section taken along line 7-7 of Fig. 6, and

Fig. 8 is an enlarged, fragmentary, vertical section taken along line 8--8 of Fig. 6.

Referring now in detail to the drawings, there is shown therein a conveyor for advancing racks, of which racks 10, 11 and 12 are shown, through an acid dipping tank 13 lled with nitric acid, a rinsing tank 14 filled with rapidly circulating water to rinse the acid from the articles, a nickel flash plating bath 15 in which the ash coating nickel is plated on the articles, a cold rinse bath 16 which rinses the electrolyte from the articles therefrom, an acid dipping bath 17 containing nitric acid, a water rinsing bath 18, a gold-plating bath 19, a recovery rinse 20, a second recovery rinse 21, a third recovery rinse 22, an acid bath 23, and a cold rinse 24. Elevating portions of the conveyor raise and lower the racks 10, 11 and 12, and the conveyor advances them one after another through the several baths. The racks 2,724,599 Patented Nov. 22, 1955 ice 10 are suspended from arms 31, and when each rack 10 is advanced through the gold-plating bath, a rigidly mounted contacter 32 connected electrically through the arm 31 to the rack 10 engages a cathode rail 33. Similarly, arms 34 and 35 carrying the racks 11 and 12 are connected by contactors 36 and 37, respectively, to cathode rails 38 and 39, respectively, so that each of the racks 10, 11 and 12 receives current from an individual one of the cathodes 33, 38 and 39. A control circuit shown in Figs. 3 and 4 controls the quantity of current forced through the articles of cach of the racks 10, 11 and 12 from a powerline 40, a control circuit 41 controlling the quantity of electricity owing through each of the racks 10 from the cathode rail 33, a control circuit 42 controlling the quantity of electricity forced through the articles on each of the racks 11 from the cathode rail 38, and a control circuit 43 identical with the control circuits 41 and 42 controlling the quantity of electricity forced through the articles on each of the racks 12 from the cathode rail 39.

The conveyor includes a chain 50 advanced along an endless track 51 by an electric motor 52 (Fig. 2)

through a driving system of well-known construction. The arms 31, 34 and 35 are mounted on and electrically insulated from carriers 53, 54 and 55 (Fig. 6) freely slidable along vertical guides 56, 57 and 58 carried with the chain 50. As each carrier is advanced to the goldplating tank 19, the carrier is supported in a raised position by a guideway 65 (Figl 6) on which rollers 66 fastened to the carrier ride, which keeps the rack above the tank 19. As each of the guides reaches the position of the righthand guide 58 shown in Fig. 6, the conveyor chain is stopped and an elevator plate 67 (Fig. 8) of an elevator 73 lowers the carrier to immerse the rack carried thereby in the gold-plating tank in a first plating position, and moves the contactor carried thereby into engagement with the one of the cathode rails 33, 38 and 39- for which the contactor is set. The plate 67 (Fig. 8) is spring-held in its position shown in full lines after being moved to that position by a stop 68 as the elevator 73 is lowered to its plating position so that the plate 67 clears the roller 66 when the plate 67 is raised with the elevator 73. A stop 69 moves the plate 67 to its position shown in broken lines as the elevator 73 reaches its uppermost position and is spring-held in the brokenline position in which the plate 67 will project under the roller 66 of a carrier when the carrier is moved to the first plating position.

Prior' to the next movement of the conveyor chain 50, a motor 70 drives a pickup chain 71 to move a lug 72 under' the roller 66 of the carrier in a fourth position, which is a drip position, the position occupied by the lefthand carrier 55 in Fig. 6, to raise the rack carried thereby above the level of the tank 19 and the roller 66 above the broken-line position of the elevator 73 out of the gold-plating solution to permit the solution to drip from the rack. The elevator 73 is raised to its brokenline position on the next movementl of the conveyor, and the chain moves all the carriers to the left, as viewed in Fig. 6, the distance between the first plating position and a second'plating position midway between the first and third plating positions and occupied by the carrier 54 in Fig. 6. A stationary rail 76 engaged by the rollers 66 supports, with one of the cathode rails 33, 38 and 39, each carrier when the carrier is in the first, second and third plating positions. The carriers just moved from the fourth position then are supported by the elevator. Simultaneously, the carriers in the first, second and third plating positions are moved to the second, third and fourth positions without being raised, the escapement elevator plate 67 is raised and the carrier 53 just behind the carrier 55 in the second plating position of the goldplating tank is moved onto the elevator plate 67. The chain 5t) then is stopped, the elevator plate 67 lowers the carrier 53 on the plate 67 to the rst plating position, immersing the rack carried thereby, and theI elevator 73 is movedl from its broken-lineposi'tion to immerse the racks in the baths 2t), 21, 22, 2'3V and 24. i

As each carrier 53 arrives at the rst plating position, the drive of the chain closes a limit switch 80 (Fig. 3), and holds the switch Si) closed until the carrier 53 (Fig. 6) is started to be moved to the second plating position when the switch is opened. As the carrier 53 is moved into the tirst plating position, the drive of the chain 50' also closes a limit switch 81 and holds the switch 81 closed until the carrier 53 is moved to the third plating position, in -which position the drive of the chain 50 opens the switch 81. Closing the switch closes a circuit through a secondary winding 82 of a transformer 3 supplied with power from conductors 84 and 85 connected to a powerline 86, a rectifier 87, a relay winding S8, a normally closed relay contact 92, a winding 93 of an ampere-minute meter 94 having an armature 95, a contact 96, the cathode rail 33, the contactor 32, the articles on the rack 10, the gold-plating solution in the tank 19 and gold anodes 10d-100. This energizes the relay winding 8S' which closes relay contacts 161 and 162. Closing the contact 101 energizes relay winding 193, which closes a holding contact 104 and opens the contact 89. Closing the Contact 102 energizes relay windings 111 and 112 and a timer clutch 'winding 113. Energization of the winding 111 closes a holding contact 115, and opens a contact 116. VThe closing of the contact 116 energizes relay winding 117 of a ratchet relay of well-known construction. On one energization of the relay winding 117, it closes a relay contact 118- and holds it closed until the winding 117 is deenergized and again energized, which opens the contact 118. Thus, the contact 11S is closed only on alternate energizations of the winding 117, and is open alternately therewith.

Whenever the contact' 118 is closed, relay windings 119 and 120 are energized. The winding 119 opens contacts and closes contacts 127. On the succeeding energization of the winding 117, the winding 119 is deenergized to open the contacts 127 and close the contacts 125. The contacts 125 are in series with a split inductance coil 126, and the contacts 127 are in series with a split inductance coil 128. When the contacts 125 are opened, the effect of a pointer 136 having a blade tip composed of a metal' having a substantially different permeability from that of air in the coil 126 is cut oli, and

.e current in an oscillatory circuit 131 (Fig. 5) is substantially reduced. The coils 126 and 128 are adiustabiy mounted and may be moved closer together or farther apart. The circuit 131 includes a vacuum tube 132, a tuned plate tank circuit 133 and a grid tank circuit 134. The grid tank circuit is connected by conductors 136 to t'ne contacts 125 and 127. The oscillatory circuit includes a transformer 140 connected by conductors 141 and 142 to the conductors 84 and 85, and a relay winding 143, which is energized only by tube 132 pl'atecurrent when the oscillatory circuit is in normal condition. The circuit 131 is such that when the magnetic tip of the pointer 139 is between windings of one of the coils 126 and 123 having the contacts 125 or 127 associated' there with closed, the change in inductivev rcactance from the magnetic tip of the pointer 13d reduces sharply the plate current in the circuit 131 to deenergize the winding 143, and a contact 145 opens. Whenever the tip of the pointer 13@ is not in the air gap of the one of the coils 12'6 and 12S whose contacts 125 or 127` are closed', the circuit 131 keeps the relay winding 143 energized to maintain the contact 145 closed. The relay winding 103 when energized opens the relay contact 89',v deenergizes the relay winding S8 and the relay contact 102 is opened after the holding contact 115 is closed, the contact 145 remaining closed until the pointer 130 is. driven by the 4, armature 95 from its position at the coil 126 to the coil 128.

immediately upon energi'zation of the relay winding 120, the contacts 92 and 96 are opened and contacts 150 and 151 are closed to reverse the direction of flow of current through the meter winding 93 to drive the armature 95 in a direction driving the pointer 130 in a clockwise direction, as viewed in Fig. 3. The relay contacts 92, 93, and 151 are of an overcenter type in which on energization of the relay winding 120 closes the contacts 150 and 151, and opens the contacts 92 and 96, and when deenergized opens the contacts 150 and 151 and closes the contacts 92 and 93. Hence, on` each energization and'deenergi'zation of the winding 120, the direction of travel of the armature 95' is reversed, and the pointer 130 is driven from the coil 126 to the coil 12S when the contacts 150 and 151 are open and the contacts 92 and 96 areclosed.

When the relay winding 112 is energized, it closes a contact closes a contact 161 and opens a contact 162 in parallel with the limit switch 81. When the contact 102 is closed by the winding. 8S, a relay winding 165 is energized to close contact 166. Current then Hows t'o the cathode rail 33 throughY a low resistance strike voltage path including the contact 160, the contact 166 and rheostats 167 and 168. Simultaneously, it ows through a higher resistance plating voltage path, which is in parallel with the strike voltage path and includes rheostats and 171 and the contact 161. The rheostats 167 ancl 168 are set to apply a higher potential between the anode 10U and the cathode rail 33 than are the rheostats 170 and 171. Hence, a high strike current is forced through the articles on the plating rack 10 when the contact 166 is closed.

Also, upon closing the swtich 102, the relay winding 113 is energized to close a contact 180 to energize a timer motor 181 of an adjustable timer. The timer motor 181 runs for a predetermined period of time, which is the time necessary to apply a predetermined amount of electricity at the strike voltage to articles being plated, and then opens a contact 182 to drop out the relay winding 165 and holds the contact 182 open until the control circuit 41 is reset. Deenergization of the relay winding 165 opens the contact 166 to break the strike voltage path to the cathode rail 33, and the plating current, which is substantially lower than the strike current, flows through the plating voltage path including the rheostats 170 and 171 and the contact 161. Energization of' the relay winding 111 closes a switch 185 toa voltmeter 186.-

The plating. current continues driving the armature 95 of the ampere-minute meter 94 until the armature 95 rotates' the tip of the pointer 130 into the air gap of the coil 128, at which point a predetermined quantity of plating electricity has flowed. When this occurs, thc balance of the oscillatory circuit is upset, and the oscillator plate current is reduced to a lowl level to deenergiZe relay winding 143 (Fig. 5) so that the Contact 145 is opened. When the contact 145 opens, the relay v/i'ndings 111, 112, 113 and 165 andthe timer motor 181 are deenergized. Deenergization of the relay winding 112 opens' the contacts 160 andv 161 to stop the plating current' through the cathodev rail 33. Deenergiza't'ion of the relay winding 111 opens the holding contact 115 and the contact 185 to' the voltmet'er 186. Deenergization of the relay' winding'. 111 also closes the Contact 116, which energizes the relay' winding 117. This does not open the relay contact 118 at this time, but d'oes so on the next energization of the winding. 1:17 to deenergize the relay' windings 119 and 120'. The d'eenergization of the winding 119 reverses the settings of the. contacts 1 25 and 12T, and deenergization of, the winding 120 reverses the setting of. the. contacts 92,v 96, 150 and. 151. to reverse the/current. ow through the winding 93, andthe direction of travel of the armature 95V willV be rc S versed, thereby reversing the directional travel kof the magnetic pointer 130 from the coil 128, which is deenergized, toward the coil 126, which is energized.

When the contacts 127 are open and the contacts 125 are closed, the oscillatory circuit of the electronic relay 131 is restored to energize the relay winding 143 and reclose the contact 143 preparatory to the next cycle. However, closing of the contact 145 does not energize any of the relay windings in series therewith inasmuch as the holding contact 115 is open and the contact 102 is open.

The ampere-minute meter 94 may time out as described hereinabove when the plating rack contacting cathode rail 33 associated with the meter 94 is in the first plating position in the tank 19, the second plating position or the third plating position depending on where the coils 126 and 128 are positioned relative to one another, and the plating rate, which regulates the quantity of electricity forced through the articles `on the plating rack 10. The ampere-minute meter 94 usually times out when the rack is in the third plating position. When therack 10 is moved from the first plating position to the second plating position, and from the second plating position to the third plating position, the plating of the articles on the rack continues without interruption, provided the meter 94 has not timed out. However, when the conveyor chain 50 moves the rack 10 from the second position to the third plating position, the drive driven by the motor 52 opens the limit switch 81, and holds open the limit switch 81 while the rack 10 is in the third plating position. Then assuming that the meter 94 times out before the next scheduled operation of the conveyor drive, the relay winding 112 is deenergized to close the contact 162-in parallel with the limit switch 81. This energizes a relay winding v190 to close a relay contact 191 (Fig. 4) through a mechanical connection 192 to energize a relay winding 193. Energization of the relay winding 193 closes a contact 194, and opens a contact 195 in series with abell 196.

As the elevator 73 (Fig. 6) reaches itsv immersing position, it opens a limit switch 200 to drop out a relay winding 201 to open the holding contact 202 thereof and also open contacts 203 leading to the motor 52, which is the prime mover of the conveyor. This deenergizes the motor 52 and also deenergizesa brakereleasing winding 205 to stop the conveyor drive. The movement of the elevator 73 to its immersing position also closes limit switches 210, 211, 212 andl 213. Closing the limit switches 210 and 211 energizes a delayed-setdown timer motor 214, which after a predetermined period of time closes a contact 215 to energize a relay winding 216. This closes contacts 217 and 218 to energize a motor 219, which drives a chain 226 (Fig. 1),t o lower' a rack into the nitric acid bath.13 and open y the limit switch 211 at the end of its travel.

The closing of the limit switches 210 and 213 also cause energization of a second delayed-set-down timer motor 220. After a predetermined time, the timer motor 220 closes a contact 221 to energize a relay winding 222. This closes contacts 223 and 224 to start a set down motor 225, which drives a chain 227 to lower the rack positioned over the nitric acid tank 17 into that bath and open the limit switch 212 at the en d o f its travel. y

The closing of the switch 210 also closes an `advancepickup timer motor 230 to be energized in a predetermined period of time, about thirty seconds, and thereafter the timer motor 230 closes a contact 231 to energize a relay winding 232. This closes contacts 233 and 234 to the advance-pickup motor 70, which raises through the chain 71 the rack` in the fourth or drip position in the gold-plating tank 19 to permit the gold-plating solution to drip backinto the tank 19 prior to thetime in which an immersion timer motor 240 times out. As this rack reachesl the level of the upper position of the elevator 73, the chain 71 opens lthe limit switch 213 andl closes a contact 239vthereof. When the timer motor 240 times out, it closes a contact 241 to energize the relay winding 201, provided the contact 194 has been closed, and this closes the contacts 203-203 to the motor 52 to energize the motor 204 to raise the elevator 73, to lift all the racks in vertical alignment with the elevator 33 to their raised positions, to advance the chain 50 one position, thereby advancing the guides 56, 57 and 58 one position, and then lowers the new racks into several tanks. As the elevator 73 reaches its lowermost position, it opens the limit switch 200 to stop movement thereof. If the contact 194 is not closed by the closing of all the contacts 191, 262' and 263 in series with the winding 193, the motor 52 is not energized and the bell 196 is rung to indicate that the plating circuit for the rack in the third plating position had not timed out. The contacts 262 and 263 are closed by timing out of the control circuits 42 and 43respectively, when the racks controlled thereby are a in the third plating position, and are closed when in the first and second plating positions by the operation of the limit switches corresponding to the limit switch 81. The contact 239 is connected mechanically to the limit switch 213 and is opened when this limit switch is closed, and is closed when this limit switch is opened. This arrangement prcvents the conveyor drive motor 204 from starting before the operation of advance-pickup motor has been completed. The limit switch 213 is closed the contact 239 is opened by the elevator 73 as the elevator 73 reaches, its uppermost position to move through an arm 269, a switch arm 270 of the switch 213 past a lug 271 of the chain 71. However, the limit switch 200 and the holding contact 202 are closed at this time to maintain the motor 52'energized.. The switch 213 and the contact 239 remain closed and open, respectively, until `the lug 271 makes a complete revolution when the chain 71 is again driven.

Operation Assuming that the elevators 67 and 73, which operate together, have just been lowered to their immersing positions to lower the carriers supported thereby to the several plating and rinse tanks and one of the carriers 53 to the first plating position with the contactor 32 in engagement with the cathode rail 33, that the immediately preceding 4carrier 55 is in the second plating position, that the carrier 54 just ahead of that carrier 55 is in the third plating position, and that the carrier 53 just ahead of that carrier 54 is in the drip position, the movement of the elevator 73 to its lowermost or plating position opened the limit switch 200 to drop out the relay winding'201 to'stop the motor 52 and apply the brakel to the conveyor drive. The movement of--the elevator 73 to this position'also closes the limit switches 210,211 and 212, and the closing of the limit -swtich 210 energizes the timer motors 214, 240, 220 and 230, and these timer motors begin to run. The timing period of the timer motor 240 is longer than those of the timer motors 214, 220 and 230, so that these latter timers time out prior to the timing out of the timer motor 240. The timer motors 214 and 220 time out predetermined periods of time before the `timer motor 240- times out, and close the contacts '215 and 221 .to energizerelay windings 216 and ',222 to Aenergize motors 219 vand 225 to lower carriers to the nitric acid baths so that articles carried by the platers will be'subjected to the nitric acid baths for Aonly the differences in the timing periods between the motors 214 and 220 on the one hand and the timer motor 240 on the other hand. Similarly the advance pickup motor 70 times out suiciently before the immersion timer motor 240 that the rack in the drip position has ample dri ping time before the operation of the conveyor'. When the contactor 321 engages the cathode rail 33, the limit switch's having been'closed by theconveyor :arenosov drive during the lowering of the elevator 67 to its immersing position, current flows through the contact 89, the relay winding 88, the ammeter 90, the wattmeter 91, the contact 92, the meter winding 93, the contact 96, the cathode rail 33, the contactor 32, the immersed rack 10, the articles on the rack, the gold-plating solution and gold anode 100. This immediately energizes the relay inding 88 to close the contacts 101 and 102. Closing the contact 102 energizes relay windings 111, 112, 113 and 165. Energization of the relay winding 111 closes the holding contact 115 and the contact 116. The closing of the contact 116 energizes relay winding 117 to reverse the condition of the contact 118 and reverse the condition of the relay windings 119 and 120. The relay winding 119 opens the contacts 127 and closes the contacts 125. The relay winding 120 opens contacts 92 and 96 of the meter 94 and closes contacts 150 and 151 thereof to reverse the direction of the current through the winding 93. This reverses the direction in which the armature 95 is driven, which then drives the pointer 30 in a counterclockwise direction, as viewed in Fig. 3, from a starting position with the tip of the pointer in the air gap of the coil 128 toward the coil 126.

Opening the contacts 127 places the electronic relay circuit 131 in such balance that the winding 143 is energized to close the contact 145 thereby establishing the circuit including the holding contact 115. After this occurs, the relay winding 103 closes a holding contact 104 and opens the Contact S9 to deenergize the relay winding SS, thereby opening the contacts 101 and 102. Energization of the relay winding 113 closes the contact 180 to the timer motor 181, which begins to run. During this time, the low resistance strike current path to the cathode rail 33 is closed, as well as the parallel higher resistance plating current path through the Contact 166 and the rheostats 167 and 168 so that a high, strike potential is applied across the cathode rail 33 and the anode 100, and a strike current flows from the anode 160 to the articles on the immersed rack to apply a dense, tine-grained, strongly adherent llash coating on the articles. The strike continues until the timer motor 181 times out, at which time it opens the contact 182 to deenergize the relay winding 165. This opens the contact 166 to open the low resistance circuit to the cathode rail 33, and the lower plating voltage is applied to the cathode rail 33, the current flowing through the higher resistance plating circuit including the rhcostats 170 and A predetermined period of time after the elevator 73 was lowered to its plating position, the timer motor 230 (Fig. 4) closes the contact 231 to energize the relay winding 232. The winding 232 closes contacts 233 and 234 to energize the advance pickup motor 235, and the motor 235 drives the chain 7.1 and raises the carrier 54 in the fourth position out of the plating tank 19 to permit the plating solution to drop therefrom back into the tank 19. When the carrier 54 gets to its uppermost position, the lug 271 on the chain 71 opens the limit switch 213 and closes the contact 239 thereof. A predetermined period of time later, the immersion timer motor winding 240 times out and closes the contact 241. This closes the circuit to the contact 194, and, if the Contact 262, which is openable by the timing out of the circuit 42 of the carrier 54 in the third plating position, is open, the relay 193 is deenergized and thc contact 194 is open and the contact .95 is closed to ring the bell 196. This indicates an abnormality in that the circuit 42. of the rack in the third plating position had not timed out prior to the timing out of the immersion timer motor 240. However, whenever the control circuit 42 associatcd with the cathode rail 38, which was contacted by the carrier 54 in the third position, is timed out, the contact 262 is closed, the winding 193 is energized and the Contact 19e to the winding 201 is closed. Then the winding 201 is energized to energize the brakc-releasing winding 205 and the drive motor 204. Normally this occurs before the immersion timer motor 240 times out.

The elevator 73 then raises all the carriers, except the carriers 53, 54 and 55 immersed in the tank 19, out of the baths to their uppermost levels. The conveyor is driven further by the motor 52 to move all the carriers horizontally one position and to lower and immerse the raised racks except those that go into the baths 13 and 17. The carrier 54 just behind the carrier 53 in the second position is lowered by this operation to the first plating position and the contacter 35 is brought into contact with the cathode rail 3S to actuate the control circuit 42 in the same manner that the carrier 53 actuated the control circuit 41. As the carriers 53 and 55 reached the second and third plating positions, respectively, the limit switch was opened and the limit switch of the control circuit 43 corresponding to the limit switch 81 of the control circuit 41 was opened, both being opened by the conveyor drive.

The timing cycles of the timing motors 214, 230, 240 then repeat, and the carrier 54 in the fourth positon is lifted out of the plating tank 19, and is moved to the left from the fourth position to a position over the recovery tank 20, the control circuit 42 of the carrier 54 in the third plating position having timed out and the immersion timer motor 240 having timed out. Simultaneously, the carrier 53 is moved from the second plating position to the third plating position. The elevator 73 then lowers another carrier 55 into the first plating position. As the carrier 53 is moved to the third plating position, the limit switch 81 is opened. Then when the tip of the pointer is rotated into the eld of the coil 128, it changes the inductance of the coil 128 to such an extent that the plate current of the electronic relay 131 is reduced to such an extent that the relay winding 143 is deenergized to open the contact 145.

Opening of the contact breaks the circuit to the windings 111, 112 and 113 and the timer motor 181 resets to zero. Deenergization of the relay winding 111 opens the contact 185 to the voltmeter 186, and opens the holding contact 115. Deenergization of the relay winding 112 opens contacts 160 and 161, and, the limit switch 80 having been previously opened, current is cut off from the articles on the rack 10. Deenergization of the winding 112 also closes the contact 162. Also deenergization of relay winding 112 closes the contact 162 to energize the relay winding 190, which causes the contact 191 to be closed, thereby assuring energization of the relay winding 193 with the consequent closing of the contact 194 and the opening of the contact 195. Hence, when the limit switch 239 is closed and the contact 241 is closed by timing out the immersion timer 241.1, the relay winding 201 is energized to aetuate the drive motor 52 to advance the carriers one position. if the meter 94 has not timed out at the time the immersion timer 240 times out, the relay winding is maintained in a deenergized condition to keep the relay winding 193 deenergized, which keeps the contact 194 opened and the contact 195 closed. Hence, the contacts 239 and 241 being closed, the winding 201 is not energized and the bell 196 is energized to indicate an abnormal condition in the plating to the operatm` of the apparatus. The abovevdcscribed cycle then repeats itself as the next carrier 53 reaches the first plating position.

The immersion timer motor 240 should be so adjusted that the total time of three cycles thereof is greater than the time necessary for any desired plating time for the carriers 53, 54 and 55. It will be noted that each of the circuits 41, 42 and 54 may be set to apply a different voltage, different strike and plating current and different quantities of electricity so that three types of articles may be processed simultaneously by the apparatus.

Certain features of the above-described apparatus are disclosed and claimed in my copending application Serial No. 231,343, filed June 13, 1951, for Control Appare tus and copending application Serial No. 231,353, filed I une 13, 1951, b y L. G. Hakes of Methods of and Apparatus for Electroplating Articles.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall Within the spirit and scope thereof.

What is claimed is:

l. An apparatus for electroplating articles, which comprises an elongated plating tank for a plating solution, anode material extending along the tank, a plurality of carriers for supporting racks and connected electrically thereto, a plurality of racks for .carrying articles to be plated, conveyor means for lowering the racks one at a time into the tank, advancing them along a predetermined path through the tank, lifting them from the tank, holding the lifted racks over the tank and moving the lifted racks beyond the tank, said conveyor means serving to keep each rack in the tank for substantially the same period of time, a pluralityv of 'cathode rails extending coextensively in parallel laterally spaced positions adjacent to said path through the tank, contactors mounted on some of said carriers for engaging one of the cathode rails as each of the last-mentioned carriers is lowered by the conveyor means to place the rack carried by the carrier in the tank, contactors carried by others of the carriers for engaging a second one of the cathode rails, means for applying sequentiallya strike potential and a plating potential individually to said cathode rails andthe anode material, means individual to each of the cathode rails for metering the quantity of electricity forced through each of the cathode rails, means responsive to the metering means for actuating the potential-applying means to change from a strike `potential to a plating potential, means responsive to the metering means for stopping the flow of electricity to the cathode rail associated therewith when a predetermined quantity of electricity has flowed through the carrier in engagement with that cathode rail, and means for preventing movement of a carrier beyond the cathode rail it is engaged with before the operation of the stopping means.

2. An electroplating apparatus, which comprises an electroplating bath having an entrance end and an exit end and having a plurality of spaced plating positions and a drip position located adjacent to the exit end thereof, an anode, a plurality of carriers for supporting articles to be plated, endless conveying lmeans operable when actuated for lifting one carrier from the exit end of the bath, moving the carriers in a predetermined path the distance between two adjacent plating' positions and lowering one carrier into the entrancev end of the bath, said conveying means serving to keep eacharticle in the bath for substantially thek same y period of time,I electrical means for normally actuating the conveying means at predetermined intervals, a plurality of cathode rails extendingl coextensively in parallel laterally spaced positions adjacent to said path through the tank, means including contactor means individual to the carriers engaging the cathode rails individually for applying individual plating voltages across the carriers in the plating positions and the anode to causeA currents to flow between the anode and articles supported by the last-mentioned carriers, means individual to each cathode rail for measuring the quantity of electricity forced through each carrier as the carrier is in said plating positions, means responsive to the measuring means for preventing operation of the electrical means prior to the passage of a predetermined quantity of electricity through one of the carriers prior to movement to the drip position from.the plating position adjacent to the .drip position, 4and timed means for raising the carrier in the drip position from the bath a predetermined period. oftimeprior toeach operation of the .conveying means topermitelectrolyte id on an article carried byA that carrier to drain into the bath.

3. An electroplating apparatus, which comprises a plating bath having an entrance end and an exit end and also provided with a plurality of plating positions spaced therealong from the entrance end toward the exit end and a drip position at the exit end, an anode extending along the bath, a plurality of cathode rails extending parallelly along the bath from the plating position nearest the entrance end to the plating position nearest to the drip posi` tion, a plurality of carriers for supporting articles to be plated, a plurality of contactors for engaging the cathode rails, said contactors beingl connected to the carriers in positions forming a given repetitive pattern such that only one carrier is connected to one of the cathode rails at any instant, conveyor means for sequentially moving the carriers at the bath along Ithe bath and in engagement with the cathode rails the distance between adjacent plating positions and lowering a carrier at the entrance end of the bath to the bath to immerse in the bath an article carried thereby and contact one of the cathode rails with the contactor connected to that carrier, said conveyor means serving to keep each article in the bath for substantially the same period of time, an electric motor for driving the conveyor means, timed means operable as each carrier is lowered into the plating position most adjacent to the entrance end of the bath for connecting the motor to a current source a predetermined period of time after the last-mentioned carrier reaches said last-mentioned position, a plurality of control circuits connected individually yto the cathode rails, each contro] circuit including means for applying a voltage across the anode and the cathode rail to which it is connected, resettable means for measuring the quantity of electricity ilowed between the the last-mentioned cathode rail and the anode, switch means for preventing operation of the electric motor when open, means responsive to the measuring means for closing the switch means to set up the electric motor for operation when the measuring means has measured a predetermined quantity of electricity and means for resetting the measuring means as each contactor set for the cathode rail associated therewith tirst engages that cathode rail, and means for raising away from the bath each carrier in the drip position a predetermined period of time before each operation of said timer to actuate the electric motor.

4. An electroplating system, which comprises a bath for holding an electrolyte, an anode in thev bath, a carrier for moving an article into and through the bath, contact means located adjacent to the bath, a contactor carried by the carrier and connected to the article for engaging the contact means as the carrier moves the article into the bath, means for applyinga voltage across the contact means and the anode, a meter responsive to quantity of electricity passed therethrough, means alternately operable for connecting reversibly the meter in series with the voltage-applying means and the'contact, means operable by movement of the carrier to the bath for actuating the connecting means, a pointer driven reversibly by the meter along a predetermined path, a coil positioned at one end of the path, a second coil positioned at the other end of the path, an oscillatory circuit having a tank circuit, means responsive to said actuating means for alternately connecting said coils to the tank circuit, relay meansenergiz'able by the oscillatory circuit for breaking the connection between the anode, the contact means and the voltageapplying means when the pointer is adjacent to the one of said coils connected to the oscillatory circuit, and means operable by `the relay means for preventing operation of the carrier prior to actuation of the relay means by the oscillatory circuit.

5. .An electroplating apparatus, which comprises -an elongated bath for holding an electrolyte therein.- and also provided with an entrance end and an exit end, an anode extending along the-bath, a,A pluralityv of cathode rails extending along the bath in parallel spaced positions, a plurality of carriers for supporting articles to be plated, conveyor means carrying the carriers in spaced positions and operative cyclicly for raising one of the carriers near the exit end of the bath from the bath, moving other of the carriers at the bath along the bath from the entrance end thereof toward the exit end thereof a distance such that the carrier next to said raised carrier is moved to the exit end of the bath and lowering one of the carriers to the entrance end of the bath, contactors mounted on the carriers in such positions that only one contactor engages each of the cathode rails at any instant, an electric motor for driving the conveyor means, a control relay for regulating energization of the motor, a limit switch for actuating the relay to a motor deenergizing condition as each carrier is lowered to the entrance end of the plating bath to stop the conveyor means, timing means having a contact in series with the control relay winding and in parallel with the limit switch for closing the contact a predetermined period of time after ore of the carriers is lowered in the bath at the entrance end thereof, a plurality of independent, adjustable means individual to each of the cathode rails for applying voltages to the cathode rails and the anode, a plurality of adjustable metering means associated individually with the voltage-applying means, each metering means serving to render the voltage-applying means associated therewith inoperative after a predetermined quantity of electricity has tiowed through the contactor engaging the cathode rail associated with that voltage-applying means, a second relay having a contact in series with the control relay winding and the timing means contact, and means operably by each metering means when the carrier contacted to the cathode rail associted therewith is at the end of said cathode rail nearest the exit end of the bath and said metering means has rendered the voltage-applying means associated therewith inoperative for actuating the second relay to close the ccntact thereof.

. 6. An electroplating apparatus, which comprisesfa platlng bath having an entrance end and an exit end and also provided with a plurality of plating positions spaced therealong from the entrance and toward the exit end and a drlp position at the exit end, an anode extending along the bath, a plurality of cathode rails extending parallelly along the bath from the plating position nearest the entrance end to the plating position nearest to the drip position, a plurality of carriers for supporting articles to be plated, a plurality of contactors for engaging the cathode rails, said contactors being connected to the carriers 1n positions forming a given repetitive pattern such that only one carrier is connected to one of the cathode rails at any instant, conveyor means for sequentially moving the carrlers at the bath along the bath and the cathode rails the distance between adjacent plating positions and towering a carrier at the entrance end oi the bath to the hath tc immerse in the bath an article carried thereby and contact one of the cathode rails with the contactor connected to that carrier, an electric motor for driving the conveyor means, a current source, timed means operable as each carrier is lowered into the plating position most adjacent to the entrance end of the bath for connecting the motor to the current source a predetermined period of time after the last-mentioned carrier reaches said lastinentioned position, and a plurality of control circuits connected individually to the cathode rails, each control circuit including means for applying a voltage across the anode and the cathode rail to which it is connected, a reversible meter connected to the cathode rail and the anode, means operable on each cycle of the control circuit for reversing current flow therethrough, a pointer driven reversibly by the meter along a predetermine path, a. coil mounted at one end of said path, a second coil mounted at the other end of said path, an oscillatory system having a tank circuit, means operable on one cycle of the control circuit for connecting the first coil to the tank circuit and disconnecting the second coil from the tank circuit and on alternate cycles connecting the second coil to the tank circuit and disconnecting the iirst coil from the tank circuit, said pointer when moved to a position adjacent to the one of the coils connected to the tank circuit serving to upset the balance of the oscillatory system, and a relay associated with the oscillatory system closing the circuit through the cathode rail and the anode when the oscillatory system is balanced and opening that circuit when the balance of the oscillatory system is upset, said relay serving when closing said lastrnentioned circuit to prevent the timed means from connecting the motor to the current source.

7. An electroplating apparatus, which comprises an electroplating bath having an entrance end and an exit end and having a plurality of spaced plating positions and a drip position located adjacent to the exit end thereof, an anode, a plurality of carriers for supporting articles to be plated, conveying means operable when actuated for lifting one carrier from the drip position, moving the Carriers in a predetermined path laterally the distance between two adjacent plating positions and lowering one carrier into the entrance end of the bath, said conveying means serving to keep each article in the bath for substantially the same period of time, electrical means for normally actuating the conveying means at predetermined intervals, means including a plurality of spaced cathode rails adjacent said predetermined path for applying individual plating voltages across the carriers in the plating positions and the anode to cause currents to ow between the anode and articles supported by the lastmentioned carriers, individual resettable means for measuring the quantity of electricity forced through each cathode rail and carrier when the carrier is in said plating positions, means responsive to the measuring means for preventing operation of the electrical means prior to the passage of a predetermined quantity of electricity through the carrier next to the drip position, and timed means for raising the carrier in the drip position from the bath a predetermined period of time prior to each operation of the conveying means to permit electrolyte on an article carried by that carrier to drain into the bath.

8. An electroplating system, which comprises a bath for holding an electrolyte, an anode in the bath, a carrier for moving an article along the bath, contact means located adjacent to the bath, a contactor carried by the carrier and connected to the article for engaging the contact means as the carrier moves the article into the bath, means for applying a voltage across the contact means and the anode, a meter responsive to quantity of electricity passed therethrough, means alternately operable for connecting reversibly the meter in series with the voltage-applying means and the contact, means operable by movement of the carrier to the bath for actuating the connecting means, a pointer driven reversibly by the meter along a predetermined path, a split coil positioned at one end of the path, a second split coil positioned at the other end of the path, an oscillatory circuit having a tank circuit, means responsive to said actuating means for alternately connecting said coils to the tank circuit, relay means energizable by the oscillatory circuit for breaking the connection between the anode, the contact means and the voltage-applying means when the pointer is adjacent to the one of said coils connected to the oscillatory circuit, and means responsive to said relay means for preventing movement of the carrier from the bath prior to the operation ot the relay means.

9. An apparatus for electroplating articles, which comprises an elongated plating tank having plating solution therein, an anode extending along the tank, a plurality of carriers for supporting articles to be plated and connected electrically thereto, conveyor means for lowering the carriers one at a time to lower the articles into the tank, advancing them along a predetermined path through the tank, lifting them from the tank and moving the car- 13 riers beyond the tank, said conveyor means serving to keep each article in the tank for substantially the same period of time, a plurality of cathode rails extending in parallel, laterally spaced positions adjacent said path through the tank, a contactor mounted on and con nected to one of the carriers for contacting one of the cathode rails as that carrier is lowered by the conveyor means to place the article carried thereby into the tank, a second contactor mounted on and connected to a second one of the carriers for contacting a second one` oi" the cathode rails, means for applying potentials individually to said cathode rails and the anode, a plurality of means for metering individually the quantity of electricity forced through each of the cathode rails, and a plurality 14 of means each responsive to one of the metering means for changing the potential between the anode and the cathode rail associated with that metering means when a predetermined quantity of electricity has iiowed through the carrier in engagement with that cathode rail.

References Cited in the file of this patent UNITED STATES PATENTS 660,884 Boissier Oct. 30, 1900 1,527,095 Turnock Feb. 17, 1925 1,712,284 Turnock May 7, 1929 1,809,138 Miller June 9. 1931 

1. AN APPARATUS FOR ELECTROPLATING ARTICLES, WHICH COMPRISES AN ELONGATED PLATING TANK FOR A PLATING SOLUTION, ANODE MATERIAL EXTENDING ALONG THE TANK, A PLURALITY OF CARRIERS FOR SUPPORTING RACKS AND CONNECTED ELECTRICALLY THERETO, A PLURALITY OF RACKS FOR CARRYING ARTICLES TO BE PLATED, CONVEYOR MEANS FOR LOWERING THE RACKS ONE AT A TIME INTO THE TANK, ADVANCING THEM ALONG A PREDETERMINED PATH THROUGH THE TANK, LIFTING THEM FROM THE TANK, HOLDING THE LIFTED RACKS OVER THE TANK AND MOVING THE LIFTED RACKS BEYOND THE TANK, SAID CONVEYOR MEANS SERVING TO KEEP EACH RACK IN THE TANK FOR SUBSTANTIALLY THE SAME PERIOD OF TIME, A PLURALITY OF CATHODE RAILS EXTENDING COEXTENSIVELY IN PARALLEL LATERALLY SPACED POSITIONS ADJACENT TO SAID PATH THROUGH THE TANK, CONTACTORS MOUNTED ON SOME OF SAID CARRIERS FOR ENGAGING ONE OF THE CATHODE RAILS AS EACH OF THE LAST-MENTIONED CARRIERS IS LOWERED BY THE CONVEYOR MEANS TO PLACE THE RACK CARRIED BY THE CARRIERS IN THE TANK, CONTACTORS CARRIED BY OTHERS OF THE CARRIERS FOR ENGAGING A SECOND ONE OF THE CATHODE RAILS, MEANS FOR APPLYING SEQUENTIALLY A STRIKE POTENTIAL AND A PLATING POTENTIAL INDIVIDUALLY TO SAID CATHODE RAILS AND THE ANODE MATERIAL, MEANS INDIVIDUAL TO EACH OF THE CATHODE RAILS FOR METERING THE QUANTITY OF ELECTRICITY FORCED THROUGH EACH OF THE CATHODE RAILS, MEANS RESPONSIVE TO THE METERING MEANS FOR ACTUATING THE POTENTIAL-APPLYING MEANS TO CHANGE FROM A STRIKE POTENTIAL TO A PLATING POTENTIAL, MEANS RESPONSIVE TO THE METERING MEANS FOR STOPPING THE FLOW OF ELECTRICITY TO THE CATHODE RAIL ASSOCIATED THEREWITH WHEN A PREDETERMINED QUANTITY OF ELECTRICITY HAS FLOWED THROUGH THE CARRIER IN ENGAGEMENT WITH THAT CATHODE RAIL, AND MEANS FOR PREVENTING MOVEMENT OF A CARRIER BEYOND THE CATHODE RAIL IT IS ENGAGED WITH BEFORE THE OPERATION OF THE STOPPING MEANS. 